The invention concerns an injection device having a housing and having an energy storage spring for storing energy for an injection operation. This energy serves preferably for automatically inserting an injection needle, and optionally also for automatic injection of an injection liquid. The preferred field of application of the invention is an injection device for one-time use, often also referred to as a disposable syringe.
It is the object of the invention to make a new injection device available.
According to the invention, this object is achieved by having a control member which disengages a detent lug once a displacement member has traveled a predefined distance in the proximal direction. What is thereby obtained, in simple fashion, is sequential execution of the injection operation, i.e. first the injection needle (hollow needle) is inserted into the patient, and only then, when the needle is already in the subcutaneous fatty tissue, is the active ingredient present in the injection device injected.
Another way of achieving the stated object is to use a spring-loaded needle protection sleeve. Because the proximal and distal end positions of the needle protection sleeve are a function of the position of the vessel container and thus of the displacement member, these end positions can be optimally adapted to requirements before and after an injection.
Further details and advantageous developments of the invention are evident from the exemplary embodiment described below and depicted in the drawings, which is in no way to be understood as a limitation of the invention.